I have aftermarket rear control arms w/o a sway bar. Is it worth the effort to try and retrofit one? I do have the large front bar, 1 1/8" I believe.
Thanks

Well, a whole lot depends on what your car's set up is and what you intend to do with the car.

What other suspension mods have you made or is it basically stock? What purpose do you intend for the car: just driving and cruising, drag racing, carve up some corners, something else? Also, what year car is it? Is it a Chevelle coupe/sedan, wagon or El Camino?

It's a '70 SS hardtop. I have adjustable upper control arms and hop-stop bars (car used to wheel hop) and tubular lower arms w/ average gas shocks and 325-50 BFG drag radials. Poly bushings on the front components.
I drive it around town quite a bit and take it to the strip 1-2 times a year (runs hi 11s to 12.0s based on how I shift it) Not really looking for corner carving, but would like some additional stability. Maybe better shocks?
Thanks, Bruce

You want a rear bar. No question about it.